Do not lighten ANY STOCK FLYWHEEL PERIOD. It is not legal for racing and will get you hurt.

It is just as easy to modify the steel hub of an ARC wheel as to lighten a flywheel and 10 times safer (or more). I forgot to add that once the hub is finished I simply placed the ARC wheel on top of the stock wheel, aligned the magnets and marked the keyway and broached (cut) it. I check my timing with a light and it was close enough for that.

Lester, I am new at mower racing as you can probably tell. when you write ''easy to modify the steel hub'', from what l can see the steel hub is just the inner part of the billet flywheel, that sits over the end of the crank, with the o/d much smaller than the flywheel's o/d. Am l looking at a different type of steel hub to the one you are writing about? neil.

Cylinder 1 is the one closest to the flywheel. Cylinder number 2 is farther away. If you look at the flywheel the way it rotates it comes to cylinder 2 then 1. Stock timing would put the flywheel magnet centered over the breather cover when cylinder 2 is at top dead center.

Lester, I am new at mower racing as you can probably tell. when you write ''easy to modify the steel hub'', from what l can see the steel hub is just the inner part of the billet flywheel, that sits over the end of the crank, with the o/d much smaller than the flywheel's o/d. Am l looking at a different type of steel hub to the one you are writing about? neil.

Yes. For the most part ARC uses one flywheel (the aluminum part) 6011 for most mower engines. It has different hubs for different engines and starter ring gears. Each part bolts to the flywheel making production more cost effective.